Acute leukemia.

This article provides a review of the acute leukemias with updated basic and practical information. The main emphasis is on techniques used to arrive at the correct diagnosis. Although morphology and cytochemistry were the mainstays of diagnosis in the past, new developments in immunophenotyping, cytogenetics, molecular biology, and in vitro assays have improved the understanding of this disease dramatically and enable the identification of new entities with distinct clinicobiologic features.